Effects of Bacterial Endotoxin on α-Synuclein Expression in the Lymph Node Leukocytes of Rats

The effects of bacterial LPS on the expression of early apoptosis marker (annexin V) and immunoreactive α-synuclein in mononuclear leukocytes of the mesenteric lymph nodes of rats were studied in vivo and in vitro. Injection of LPS increased the number of lymphocytes with high expression of immunoreactive α-synuclein in cell nucleus and cytoplasm (by 68.6±8.1%) and stimulated apoptosis in this population (by 96.0±3.6% of the control). The expression of α-synuclein in macrophages increased only in the cytoplasm and this increase was not paralleled by stimulation of apoptosis in these cells. The data indicate that LPS-induced elevation of α-synuclein in lymphocytes is a component of the mechanism of programmed death in these cells. The increase of α-synuclein expression in macrophages can be related to processes associated with their stimulation.